SILVER SPRING, Md. — The Food and Drug Administration (FDA) has released a report on its investigation of the Salmonella Typhimurium outbreak that caused 31 reported illnesses and four hospitalizations in the United States between June and August 2021. The FDA worked with the Centers for Disease Control and Prevention (CDC) and state partners to investigate the outbreak, which was linked through epidemiology and traceback to packaged salad greens during the summer of 2021. This outbreak is believed to be FDA’s first domestic investigation of a foodborne illness outbreak associated with leafy greens grown in a controlled environment agriculture (CEA) operation. The CEA operation produces leafy greens using common commercial high density hydroponic growing techniques with deep water culture and floating raft production methods. The report released today includes an overview of the traceback investigation, investigation results and various factors that potentially contributed to the contamination of packaged leafy greens with Salmonella.
Although a conclusive root cause was not identified, the agency identified certain conditions and practices that could result in contamination, including the presence of a different serotype of Salmonella in pond water used to grow the leafy greens, growth media storage practices, water management practices and general sanitation practices at the CEA that were inadequate to prevent the introduction or spread of microorganisms of public health significance into the leafy greens.
FDA isolated the outbreak strain of Salmonella Typhimurium in a stormwater retention basin adjacent to the CEA farm. However, the investigation did not reveal if that stormwater retention basin was the source of the Salmonella that ultimately contaminated the leafy greens. This highlights the importance of assessing all microbial hazards, including those associated with adjacent and nearby land uses.
In light of this report, FDA highlights the following requirements and recommendations applicable to firms, such as the hydroponic operation implicated in this outbreak, engaged in CEA. Here are some of the requirements and recommendations:
These requirements and recommendations are just some examples that serve as a reminder that as the use of CEA is increasing globally, all types of food production must continue to address basic food safety concerns, including potential sources and routes of contamination. Food safety is a shared responsibility that involves food producers, distributors, manufacturers, retailers and regulators. Recognizing the interconnection between people, animals, plants and their shared environment when it comes to public health outcomes, we encourage collaboration among various groups in the broader agricultural community (i.e., produce growers, state government and academia) to address this issue. The FDA said…